This invention relates to an apparatus and method of controlling the cursor of a computer display and in particular to a cursor control device and method which translate motion of the head into motion of the cursor.
In many computer systems currently in use, a cursor serves as a major component of the interface between the machine and the operator of the machine. In graphics, data and word processing applications, the cursor indicates the current position of the data or text which can be edited or into which new data or text can be inserted. For many computers, the cursor is controlled simply by a key or keys on the keyboard. To move the cursor, the key or keys are depressed either a number of times corresponding to the number of position changes over which the cursor is to be moved or continuously until the cursor arrives at its desired position.
Recently, other types of cursor control devices have been developed. One such device, which is referred to as a "mouse", is designed to lie on a table or other flat surface and be moved about by hand. As the operator moves the mouse in a given direction on the table, the cursor moves in a corresponding direction. U.S. Pat. Nos. 3,541,541; 3,835,464; 3,892,963; 3,987,685; 4,390,873 and 4,409,479 provide examples of various mice.
These cursor control devices or mice operate in a number of different fashions. The mouse taught by U.S. Pat. No. 3,892,963, issued to Hawley, translates a mechanical action of bearings or other types of roller devices into an electrical signal which signifies an amount of position change. Such mechanical devices have, however, proven to be rather inconvenient to use for a number of reasons. First, when the computer is placed on a rather small table there may not be a sufficient area over which to move the mechanical device so that the wheels or other position change-indicating devices can accurately provide the full range of movement of the cursor. Second, after a substantial period of use, the mechanical moving parts of the mouse, such as the balls or wheels, become dirty and cease to provide continuous rolling action.
The "optical mouse" taught by U.S. Pat. No. 4,409,479 provides the advantage that movable parts are eliminated. This optical mouse, however, requires a significant amount of flat surface area over which is placed a special planar grid pattern for charting movement of the mouse. Also, dirt and dust will tend to block the light source or grid pattern if all of the components of the apparatus are not kept clean.
Principal among the other drawbacks of the mouse technology is that manipulating the mouse is difficult, and it often takes several hours to fully master. Once mouse manipulation is mastered, there is then the problem that it is often clumsy to go back and forth between the mouse and the keyboard when a task requires the entering of text or data into the computer. For the most part, the constant shifting required between the mouse and the keyboard makes mice virtually useless for word processing and accounting spread sheets, two of the more popular uses for personal computers with which mice are normally associated.
There are a number of other cursor control devices which suffer from any of the same shortcomings which are inherent in mice. Among these other cursor control devices are light pens, tablet pens, joy sticks, track balls and thumb wheels. For the most part, each of these devices also requires several hours of use to fully master, and the constant shifting between the cursor control device and the keyboard which is inherent in the use of mice also creates problems when using these cursor control devices.
One attempt to eliminate the problems caused by the aforementioned cursor control devices is disclosed in U.S. Pat. No. 4,369,439 issued to Broos. Broos provides a movable data entry keyboard which is mounted on a carriage. Cursor position signals are generated directly from position transducers associated with the carriage. In operation, when the operator entering data or text desires to move the cursor, a switch is activated and the keyboard is moved along a flat surface thereby resulting in corresponding movement of the cursor on the computer display. Operation of such a cursor control device is much simpler and quicker than the above-described cursor control devices because the operator's hands never leave the keyboard. The keyboard is, however, larger than conventional mice, and as a result, an area even greater that that required for mice is required for moving the keyboard. In addition, this cursor control device will require some start up learning time, and there will be some inconvenience associated with its use resulting from the fact that it is customary to type from a stationary keyboard. Typing from a constantly moving keyboard will never be as fast and easy as typing on a standard stationary keyboard.
It is therefore a principal object of the present invention to provide a cursor control device which is easy to use and which does not require significant start-up time for its initial use.
It is a further object of the present invention to provide a cursor control device which allows for simultaneous use of the cursor control device and the keyboard.
Still another object of the present invention is to provide a cursor control device which is operated by a natural and ordinary human movement.